1. Field of the Invention
The invention pertains to a detachable probe control for sensing electric utensil temperatures electronically by means of a thermistor resulting in rapid sensing of temperature changes and very accurate utensil heat control.
2. Description of the Prior Art
Electronic temperature control circuits employing thermistors have been in wide use for a number of years. A thermistor is defined as a solid state semi-conducting device having an electrical resistance which varies with the temperature. Its temperature coefficient of resistance is high, non-linear, and most commonly negative. The use of electronic temperature control for utensils has not become accepted practice, however, largely due to the lack of a suitable method of mating the sensing element portion of the electronic circuit to the utensil in such a manner that assures satisfactory thermal contact and does not interfere with generally accepted use patterns established for the electric utensil such as electric skillets. An almost universal feature on currently available electric skillets is a detachable combination power supply and thermostatic probe control unit that can be removed from the skillet as necessary for storage or cleaning purposes. The present invention offers a solution to the problem in that the sensing probe provides means for placing the thermistor in adequate thermal contact with the heated skillet surface while at the same time adequately electrically isolating it and using it in the standard-type probe so that it is readily detachable and adaptable to applications that use the standard probe design typical of the type shown in U.S. Pat. No. 3,737,623 of common assignment. The present invention is an improvement on the standard probe in using a thermistor heat sensing element and a unique supporting structure for the thermistor within a probe finger for electrically insulating it as necessary while providing good thermal conductive means to it for sensing temperature.